Certain water-soluble high molal oxyalkylated esters and method of making same



Patented Sept. 14, 1943 CERTAIN WATER-SOLUBLE HIGH MOLAL OXYALKYLATED ESTERS. AND METHOD, OF MAKING SAME I Melvin De Groote, University City, and Bernhard ,Keiser, Webster Groves, Mo.,

assignors to,

'Petrolite Corporation, Ltd., Wilmington, Del.,

a corporation of Delaware No Drawing. Original application March 21,

1941, Serial No. 384,597.

Divided and this application June 26,1942, Serial No. 448,684

11 Claims.

This invention relates to a new chemical product or compound, our present application being a division of our co-pending application Serial No. 384,597, filed March '21, 1941, now U. S. Patent No. 2,295,166, dated September 8, 1942.

One object of our present invention is to provide a new material, compound or composition of matter, that is capable of use for various-purposes, and particularly adapted for use as a demulsifier in the resolution of crude oil emulsions.

Another object of our invention is to provide a practicable method for manufacturing said new material, compound or composition of matter. a

The new chemical compound or composition of matter'which constitutes our present invention is exemplified by the acidic, or preferably, neutral ester derived by complete esterification of one mole of a polyalkylene glycol of the kind hereinafter described, with a fractional 'ester derived from a hydroxylated .material of the kind herein described, and apolybasic carboxy acid having not over six carbon atoms.

If a hydroxylated material, indicated for the sake of conveniencaby the formula T.OH, is reacted with a polybasic carboxy acid, which, similarly, may conveniently be'indicated' as being of the dibasic type, by the formula HOC.D.COOH, then the fractional ester obtained by reaction between 'equimolar quantities may by the following formula:

, v HOOC.D.COO. T'I v The polyethylene glycol may be characterized by materials of the kind such as heptaethylene glycol, octaethylene. glycol, nonaethylene glycol, decaethylene glycol, to and including heptadecaethylene glycol. -For convenience, these polyethylene glycols may be indicated by the follow- .ing formula: i

in which m varies from 7 through17..

' Instead of polyethylene glycols, one may use polypropylene glycols or polybutylene glycols. Thus, for convenience, in thebroadestaspec't, the polyalkylene glycols employed may be indicated by the following formula:

omcnninoq ,"H I

in which m'has its previous significance and n represents a numeralivarying from 2 to 4.

Thus, the bulk of the materials herein conbe indicated tcmplated, particularly for use as clemulsifiers,

may be indicated within certain-variations,as hereinafter stated, by the'neutral'ester derived ethylene groups.

by esterification of one mole of a glycol of the kind above described with two moles of a fractional ester of the kind previously described.

The-formation of the compound may be indicated by the following reaction, although obviously, it

is immaterial what particular'procedure' is. employed to produce the particular chemical-compound or product: I

As indicated previously, the polybasic acids employed are limited to the type having not more than six carbon atoms, for example, oxalic, malonic, succinic, glutaric, and adipic. Similarly, one may employ acids such as fumaric,:maleic, glutaconic, and various others, including citric, malic, tartaric, and the like. The selectionof the particular tribasic or dibasic acid employed is usually concerned largely with convenience of manufacture of the finished ester, and also of the price of the reactants. Generally speaking, the

higher the temperature employed, the easier it is to obtain large yields of the esterified product. Although oxalic acidis comparatively cheap, it decomposes somewhat readily at slightly-above the boiling point of water. For this reason, it is more desirable to use an acid which is more resistant to pyrolysis. Similarly, when a polybasic acid is available in the form of an anhydride, such anhydride is apt to produce the ester with greater case than the acid'itself. For this reason, maleic anhydride is particularly adaptable: and also, everything else considered, the cost is comparatively low on a per molar basis, even though somewhat higher on a per pound'basis. Succinic acid or the anhydride has many of the attractive qualities of maleic anhydride; and this is also true of adipic acid. For purposes of brevity, the bulk of the compounds hereinafter illustrated will refer to the use of maleic anhydride, although it is understood that'any other suitable polybasic acid may be employed. Furthermore, for purposes ofconvenience, reference is made to the use of polyethylene glycols' As has been I previously indicated, such'glycols can be'replaced bysuitable polypropylene or polybutyle'ne compounds; 1

As far as the range of oxyalkylated compounds employed as reactants is concerned, it is our preference to employ those having approximately 8-12 oxyalkylene groups, particularly 8-12 oxy- The preference to use the oxy-' ethylated compounds is due largely to the fact that they are commercially available, andparticularly so in two desirable forms. The most desirable form is the so-called nonaethylene glycol, which. although consisting largely of nonaethylene glycol, may contain small'amonnts of heptaethylene and octaethy'lene glyools. and possibly, minor percentages of the higher homologs. Such glycols represent the upper range of distillabl-e glycols; and. they may be conveniently referred to as upper distillable ethyleneelycolsi There is no particularly good procedure for making a sharper separation on a commercial scale; and t is understood that mixtures --of one "or more of the glycols may be employed, aswell as .a single glycol. As pointed out, it is particularly preferred to employ nonaethylene glycol as commercially available, although .it is understood that this product contains other homologs, as 'ihdicated.

Substantially as desirable as the d mer distillable polyethylene glycols, are the lower nondlstillable polyethylene g lycols. These materials are available in the form of a waxy Water-soluble -material, and the general range may vary some- What from decato ztetradeca-ethylene glycol.

A :is well understood, the method of producing such glyoels would cause some higher homologs to be formed; and thus, 'even this instance there may be present some oxye'thylene -gl-ycols within the higher range above indicated. One need not ,point out that these particular compounds consist of mixtures, and that in some instances, particularly desirable esters, are obtained -by making mixtures of thefliquid nonaethylene glycol with the soft, waxy, lower non- =distillable polyethylene glycols. For the sake of convenience. reference in the examples will be tononaethylene glycol; and calculations will be based on a theoretical molecular Weight of 414. Actually, in manufacture, the molecular 'weight -01 the glycol employed, whether a higher distillablepolyethylene glycol, or a lower non-distil'lable polyethylene glycol, or a mixture of the same, should be determined and reaction con- -tlucted on the basis of such determination, particularly "in conjunction with the hydroxyl or nco'tyl 'yalue.

lit been previously pointed out that it is immaterial how the com-pounds herein contemplated .are manufactured, although we have Sound it most desirable to react the selected i lysci or mixtures of glycols with maleic anhydride do a ratio-of two moles of the anhydrldefor one 1111018 .01 the glycol. Under such circumstances we have 'found little tendency to *form longer rcha'inpelymers; and iin fact, the product of reaction, iii conducted (at reasonably low tempera- ,tures, appears to belarsely monomeric. For conwenience, such intermediate product may then be meidered no .a dibasic -02 polybasic acid. One mole nf. P's-he intermediate 'so obtained is then we noted with two moles of the alcoholic material ikind .suosequentlydescribed.

it is to be noted. however, that if one preaa, fractional acidic ester, then if two moles ,-irm.tly re erred ms .hydroyylated high molal esters of monchydrdc z'a-lqolnols. They are invariablywater-insolubie. They contain at least 11 insolu ble alcohol.

carbon atoms, and may contain as many as 48 carbon atoms. They usually contain only one hydroxyl group, as, for example, when derived from "ricinolelc acid, .but in some instances, as, for example, when derived from di'hydroxystearic acid, they may contain more than one hydroxyl ,group. Since such esters are derivatives of monohydric alcohols, the vhyclroxyl group must be part of the acyl radical 'of the ester, and cannot be giant of ,the alcohol, residue, in contradistinction to esters of the lrind exemplified by mono-olein, monostearin, :etc,

Although the ,hydroxylated ester employed as a reactant in the manufacture of the compounds herein contemplated is water-insoluble, such ester may .be derived from. a water-soluble or waterlnsolublesacld, ,andifrom a water-soluble or water- Generally speaking, such water-insoluble esters are obtained by the use of either a water-insoluble acid, or a water-insoluble alcohol-ass, secondary raw material for producing the .ester. For instance, ethyl .alco'hol (a watersoluble alcohol) may be esterifled with ricinoleic :acid (a water-insoluble acid) to produce waterinsoluble ethyl ricinoleate. Similarly, water-insoluble cetyl alcohol can be reactedwith water- :soluble :lactic acid to produce the water-insoluble oe'tyl lactate. 'It is also obvious that monohydnic other alcohols willfunction in the same manner laszanalcnhol, and thus may be employed :in the productioniof the esters.

Briefly, then, the water-soluble alcohols or alcorhol ethers, which serve lag secondary raw materials for esterification to produce the Wateriinsoluble esters, include ethylene glycol monomet'hyl ether; ethylene glycol monoe'thyl ether; ethylenerglycdl monobutyl other; ethylme glycol etherj ethylene glycol monobenzyl ether: rdiethy'lene glycol. morhomethyl ether; dileilh-ylene glycol monoet-hyl et her; diethylene glycol monobutyl ether; methyl alcohol; ethyl alco- 1101; iis m upyl alcohol; normal butyl "alcohol; methyl isobutyl carbino'l; 2-ethyl 'butyl alcohol; "normal hexyl .alcohdl; various isomeric amy'l a1- cohols andlmiirtures thereof, -.etc. Other alcohols, not necessarily water-soluble, include 4-tertiary .amyl cycloh'exanol; i2,'4--diamyl cyclohexanol; pitertiary ,amyl ethanol; ditertiary amylphenoxy ethanol; methylamyl 'carbinol; octyl alcohol; 5-

ethyJnOnanoI-Z'; 7ethyl-i2-methyl undecanoll; 3,9-diethyl tridecanol-G.

Purely as a convenience, Kthen,the secondary raw materials, 1. e., the alcohols employed to produce the water-insoluble esters, maybe divided into two classes, 1. e.,' the water-soluble alcohols and :the high "molal water-insoluble alcohols. Such high :molal alcohols are invariably water- 'insoluble and contain at least 10 carbon atoms and "not more than 32 carbon atoms. They usually contain only onehydroxyl group, but in some instances, as hereinafter indicated, they may contain more than none h-Ydroxyl group. Such alcohols are generally obtained by reduction of the corresponding fatty acids or esters thereof. The reaction in its briefest :form may be indicated asfollows:

R.COOH in the above instance may represent any detergentdorming :acid, 1; e., any of a number of monocarboxy acids having more than 9 .and not over 32 carbon atoms, and characterized bythe fact that they combine with 'alkalles such .as caustic soda, caustic potash, ammonia, triethanolamine, and the like, to produce soap. or

stearic acid, palmitic acid, etc.

the higher fatty acids, other well known members include resinic acids, vabietic acids; naphthenic acidsyand acids obtained by'the oxidation of petroleum hydrocarbons, and commonly referred to as oxidized wax acids.

'm'olal type. .emplified by glycollic acids, lactic acid, hydroxy soap-like materialsf The best examples are, of course, the higher fatty acids, such as oleic acid, In addition to Generally speaking, the'higherfatty acids are apt to'contain from 12-14 carbon atoms as a lower limit, and from 18-22 carbon atoms as an upper limit. Oxidized waxes may contain as many as 30 or 32 carbon atoms. These various acids, when unsaturated,

"maybe totally or partially hydrogenated, and

then'converted into the corresponding alcohol;

The commonest use of high molal alcohols has been their'conve'rsion into sulfates or sulfonates. As to patents which specifically enumerate high molal alcohols applicable. for use as reactants in the manufacture of the present compound; see'the following:

U. S.'Patent No. 2,110,848, dated Mar. 8, 1938 to De'Groote; 2,181,172, Oct; 4, 1932, Daimler et al.; 1,916,776, July 4, 1938, Steindorff et al.; 2,106,242, Jan. 25, 1938, DeGroote et al.; 2,106,243,

Jan. 25, 1938, De Groote et al.; 2,110,847, Mar. 8, 1938, De Groote; 2,000,994, May 14, 1935, Schrauth; 2,061,617, Nov. 24, 1936, Downing et al.; 2,061,618, Nov. 24, 1936, Downing et a1. 2,061,619,

Nov. 24, 1936, Downing et al.; 2,061,620, Nov. 24,

tively *free "from the hydroxylated compounds- "Hydroxylat'ed acids are produced by other procedures, such as chlorination, either. byaddition or substitution, as, for example, chlorination 'of'ole'ic 1936, Downing et al.; 2,171,117, Aug. 29, 1939,

Schrauth; 2,187,338, Jan. 16, 1940, Werntz; 2,187,339, Jan. 16, 1940, ,Werntz; l .917,255, July 11", 1933, Harris; 2,170,380, Aug. 22, 1939, Holsten; 1,966,187, July 10, 1934, Schirm.

Chemically, it is to be noted that these alcohols represent more; than one type, i. e.,- they the following alcohols: Decyl, undecyl, dodecyl, ftetradecyl, octadecyl, cetyl, oleyl, cholesterol, "glycols of high molecular weight of the type exemplified by octadecane diol, octamethyl glycol, decamethyl glycol, and also alkyl, cycloalkyl, aralkyL or aryl ethers of the different polyhydric alcohols, such as, for example, the cres'ylic,

phenylic,. benzylic, cyclohexylic, or naphthylic ethers of glycol orglycerol. Similarly, derivatives of diphenyl, such as hydroxy diphenyl and th hydroaromatic homologs, are suitable.

The hydroxy acids, as has been suggested, may

be conveniently divided into the water-soluble,

10w molal type, and the water-insoluble, high The water-soluble type may be exbutyric acid, etc.

The highmolal alcohol acids, i. e., the high .molal hydroxy acids, are invariably water-into as hydroxylated wax acids. Hydroxylated wax acids occur as by-products in the oxidation of,

acid or stearic acid.- Subsequent reactions in"- volve the removal ofthe chlorinewith the introduction of a hydroxyliradical. .Undecylenic acid, derived from castor oil, has been converted into a hydroxy undecenoic acid. Unsaturated hydroxy acids, such'as ricinoleic acid, may be treated in various manners, so as toproduce derivatives, for example, chlorinated or brominated ricinoleic acid. Such materials are entirely satisfactoryi'or use as reactants in the preparation of materials of 'the kind herein contemplated; Naturallyoccurring naphthenic acids can also be converted into hydroxylated products by following similar procedure. An unsaturated hydroxy 'acidysuch asricinolei'c acid, can be converted into a 'hY-I droxylated arylstearic acid. Such procedure'contemplates reactions such as those involving ricinoleic acid, benzene, and aluminum chloride in large excessjor involves the desulfonation 01a sulfoaromatic' fatty acid. In an .eve'nt,.by employing derivatives of undecylenic acid, or 'one'or more of the various wax acids, naturally-occurring naphthenic acid, ricinoleic acid, diricinoleic acid, .or derivatives thereof, as have been enumerated, on'e can obtain a variety ofxhydroxylated 'monocarboxy acids,hav'ing at least 11 carbon atoms and not in excess of 36 carbonratoms. Such compounds are the kind herein contemplated as reactantsto furnish thealcoholiform hydroxyl.

Hydroxy acids of the kind herein contemplated may also be prepared by the hydrolysis of alpha- Such type of reaction, however, involves numerous difficulties; and thus, it is better to employ a hydroxy acid.

In some instances derivatives of hydroxylated unsaturated acids are most readily obtained by the employment of an intermediate in which the hydroxyl group is protected. Thus, ricinoleic acid. may be acetylated; and such acetyl ricinoleic acid converted into a derivative, for instance, a derivative in which an aryl group. is introduced. Such derivatives can then be saponified or hydrolyzed so as to regenerate the hydroxyl radical.

The actual preparation of esters and hydroxy acids is well known. 1 The commonest esters, especially those available commercially, are invariably esters of ricinoleic acid. Esters including methyl ricinoleate, ethyl ricinoleate, propyl ricinoleate, butyl ricinoleate, amyl ricinoleate, hexyl ricinoleate, octyl ricinoleate, and thelike, are'ernployed for various purposes, and particularly as a constituent of hydraulic brake fluids. In the manufacture of esters in which thereis considerable carbon atom interruptionbetween the carboxyl group and the hydroxyl group, for instance, ricinoleic acid, as compared with lactic acid, one can produce the esters in the same manner employed to produce the corresponding alpha-bromolauric acid, "alphaesters or rnonihydroxylated .xfatty, .acids, :for stmce, procedures employed :in 'ithea'matnuiactlne -01 methyl oleate, butyl cleate, :methyl stear'ate, butyl =naphthenate, "etc. Such procedures result --in the formation ofisome polyricinoleicracidsjand' possibly esters of polyricinoleic 'acids. Naturally, the; esters of polyricinoleic acids: may :be: employed in theipresent process' for iinstanoe, a methyl oster of diricinoleic zacid, or similar materials;

dls'ito the manufacture of-various esters not :the kind herein :described, attention is directed to athe following United States patentsztowitz No. 1,160,595, dated Nov. .$l'6,I :19l5', to Grlltel :24, 1939., .-'Hansley. [See els-o'Organic fi-yntheses,

wolme X,l age 88.

' It 18 "to be noted that onermay, for example, --pmduce .material'shavine' a fairly wide range, :as darts carbon atoms are concerned- For instance, snnermay employ octylv lactate :OII onehand, or else, one might produce an alcohol having agmany as -30. carbon atoms from an oxidized wax acid; and

esterlfythe same with ricinoleic acid.

F or all ;practic.a.l purposes, however, :the chest and most "desirable compounds. are obtained .from

the mcstcommonly available esters, i. ;e., the -csterszof'ricinoleic acidand. the lower alcohols of athe'kind previously. enumerated.

, Acidic intermediate prodacdflizrdmrllcl j I pound mole of nonaethylene glycolis..re-

:acted .with two pcund'mol'es of maleicanhydride, :soas to form nonaet'hylen glycol .dihydrogen dlmaleate.

' Acidic intermediate product,.'Era1npie 2 A mixture of lower non-distillable polyethylene glycols, rrepresenting approximately deca to .tetmdeca-ethylene glycol, is substituted for :nonaethylene glycol in the preceding. example.

.Acidic intermediate product, Example 3, I

:A 50f50 mixture of :nonaethylene glycol and lower .'.non-distillablepolyethylene glycols of the kind described in the :previous example iS'su-bstituted for .n-onaethylene glycol in Example :1.

in Examples 1-3, preceding.

Acidic intermediate product, Example 7 Succinic' anhydride is substituted form'aleic anhyd'ride in Examples 1-3, preceding. Themethod of producing such fractional ester is well known. The general procedure is to-emp'loy a temperature above the boiling pointof y water and below the 'pyrolytic point of the re- "actants. The products are mixed and stirred constantly during the heating and-esterification *step. If desired, an inert gas, such as dried nitrogen or dried carbon dioxide, may be passed through the mixture. Sometimes it isdesirable 'to add an esterification catalyst, such as sulfuric acid, benzene sulfonic acid, or the like. This is the same general procedure as is employed in the manufacture of ethylene glycol dihydrogen tion of matter, Examples 1- 11, inclusive, except quires =no furtherelaboration.

"ample 1.

ldipht'halate." *See U. 5; Patent No. 211753 fdated'March :30, 1937;:t0 Frasier.

Sometimes esterfication 1 is .SCOIIdil-Cbfid most ireadily in thepresencescf an inertv solvent which carries away the water of .esterficatiumthatmay be :formed, although, as is readily appreciated,

.. such water. of esterification is absimt when lthe reaction involves an acidwanhydride, such .as

maleicanhydride, and a glycol. However if wa- .ter s' formed, for instance, when citric Mid is employed, "thena solventsuchns xylene -myhe present and employedao carry off the waiter formed. The mixtureof xylene vapors and water vapors can'be condensed so thnt'thewateris separated. The xylene is thenreturned to Mac reaction wessel for iurthercirculation. .Thisris a.

conventional and well known procedure and re- Composition of matter, E ample 1 I One pound mole of theintemlcdiate-productof the kind described in Intermediateproduct, Examples 1, 2 and 3, above, is reacted with two pound molesof methyl ricinoleateuntil'all car- 'boxyl acidity has disappeared. 'lirne of may vary from a few hourstoas much as 1.20

hours.

Composition of matter, Example :2 Ethyl ricinoleate .is substituted for methyl ricinoleate in the preceding example.

Composition of matter, Example 6 Propylricincleate is substitutedi'ior methyl-11c inoleatein Composition of matter, Example 1.

Composition of matter, Example 4 if Butyl riclnoleate is substituted rm methyl 'minoleate in Composition of mattenEx-amplel,

Composition of matter, Examplefi I Amyl ricinoleate is substituted mrmem mcinoleate in Composition of matter, Example 1.

. Composition of matter, lirample "6 Hexyl ricinoleate is substituted forimethad (rioinoleate in Composition of matter ,:Example .1.

Compositi n of matter, Example 7 Methyl diricinoleate is substituted f-erimothyl ricinoleate :in Composition of matter, Example 1.

Composition ofmattr, Example '8 Ethyl diricinoleate is substituted for methyl ricinoleate in Composition of :matten-Example 11.

Composi'fiionoj matter, Example 9 Methyl 'hydroxystearate is substituted for methyl ricinoleate. in Composition of ma-tter,-Ex-

Composition fof matter, Example Ethyl hydroxystearate is substituted tor methyl .Lricinoleate in Composition 'of matter, :Example :1.

Composition of matter, Example .11

' Butyl hydroxystearate is substituted :ror methyl ricinoleate in Composition of matter, Example '1.

Composition of matter, Example 12 'The same procedure is followed'as' m Composithat an intermediate product of the kind exemplified by Intermediate product, Exampledris substituted for that in Intermediate product Ex- I Composition of matter, Example 13 Composition of matter, Example 14 The same procedure isfollowed as in Composition of matter, Examples 1-11, inclusive, except that an intermediatev product of the kind exemplified by Intermediate product, Example 6, is substituted for that in Intermediate product, Examples 1,2 and 3.

Compositi n of matter, Example 15 The same procedure is iollowedas in'Composition of matter, Examples 1-11, inclusive, except that an intermediate product of the'kind exemmined by Intermediate'product, Example '7, is substituted for that in Intermediate product, Examples 1,2 and 3.

It is to be noted that this second step' is an esteriflcation reaction, and the'same procedure is employed as suggested above in the preparation of the intermediate product; Needless to say, any particular method maybe used to produce the desired compounds of the "kind indicated. In some instances it may be desirable to conduct the esterificatio'n reaction in, the presence of anonvolatile inert solvent which simplyacts as a diluent or viscosity reducer. i VI In the preceding examples, attention has been directedprimarily to the monomeric form, or at least, to the form in which the bifunctional alcoho1 ,"-i. e,, a glycolgan'd the polyiunctionalacid, usually a bifunctional compound, r'eactto give a chain type compound in which'theadjacent acid and glycol nucleus occur as ajstructuralunit. For-instance, in the monomeric form thismaybe indicated in the following manner:

p I 1 an; ..-,'.1g1y'c-o1. ...l-. acid If, however, one prepared an intermediate product employing the ratio of three moles oi maleic anhydride and two inoles of nonaethylene glycoljthe tendency would be toproduce a productlwhich might be indicated in the following 1 acid glycol ;.-acid". {glycol acid; Similarly, three moles of the" glycol" and four moles of the acid might-tend to givea combinationwhichm'ay beindicated-thus: 1

acid glycol acid glycol. I ac1 d".'."g1ycol-. acid .Another'waybi stating the-matter is that the composition may be, indicated in the "followin manner:'...., l

in which the characters have their. previous significance and wise. 'relativelysmallswhole number less than 10.and probably less than 5; and-in the monomeric form r, of course, is 1. The' limitations on the size of a: are probably influenced largely 'by'the fact that reaction leading to furthergrowth is dependent upon. random contact. i Some of the productsare self-emulsifiableioils or self-emulsifiable "compounds; whereas, others give'cloudy solutions or sols; and the most desir able type is characterized by'glvinga clear solution in water, and usually in the presence 01 soluble calcium or magnesium salts, and frequently in the presence of significant amounts of either acids or alkalies.

Water solubility can of Ways which have been suggested by previous manufacturing directions, for instance:

. (a) By using a more highly polymerized ethylene glycol; I V I (b) By using a polymeric form instead of a monomeric form in regard to the unit which forms the chain between the two alcoholic nuclei; (0) By using a polybasic carboxy acid of lower molecular Weight, for instance, maleic acid instead of adipic acid;

- (d). ,By using an alcoholic material of lower molecular weight, for instance, methyl ricinoleate,

, instead of butyldiricinoleate.

In any event, it is to be noted thatthe com pounds of thetype herein contemplated are limited to the water-soluble type, i. e., those which are self-emulsifying in water, orproduce a sol oramolecular solution. I

Actually, a reaction involving an alcohol and an acid (esterification) amounts of either one or both of the reactants, depending upon the predetermined proportion, to, remain. in an unreacted state. In the actual preparationof compositions of the kind herein contemplated, any; residual acidity can be removed by any suitable base, for instance, am;-

monia, triethanolamine, or the like, especially in dilute solution. Naturally, precaution should be taken so that neutralization takes place without saponm'cation or decomposition of the ester. In some cases there 'isno objection to the presence of the acidic group.': Indeed, if a tribasic acid be employed in such a manner as to leave one free carboxyl group, then it is usually desirable to neutralize such group by means of a suitablebasicmaterial. I, U

In the hereto'appended claims, reierence to a neutral product reters to one in which free carboxylic radicals are absent. I

1Materials oi the kind herein contemplated may find uses as wetting, detergent, and leveling'agents in the laundry, textile and dyeingindustry'i as wetting, agents and detergents in the acid washing of fruit, in the acid washing of building stone and brick; as a wetting agent and spreader inthe application or asphalt in road building and the like, as aconst tuent of soldering flux preparations; as a flotation reagent in the flotation separation of various minerals; for flocculation and coagulationgoi' .various aqueou suspensions containin'g negatively'cnarged particles such as sewage, coal washing waste water, and various trade wastes'and the like; as germicides, insecticides, emulsifiers for cosmetics, spray oils, water-repel-' lentitextile iinish, etc. These uses are by "no means exhaustive; I I

However,v the most;:important phase of the present inventionga'siar as industrial application goes, is concernedjwith the use of the materials previously described as demulsin'ersi'or wateriii-emulsions, andmore-specliically, emulsions of water or brine in crude petroleum.

We have found thatthe particular chemical compounds or reagents'hei'em'described and desirable for-use as'demulsihers, may also be used for other purposes, for instance, as a break in ducer in doctor treatment of the kind intended to sweeten gasoline. See U. S. Patent No. 2,157,223, datedMay 9, 1939,to,Sutton.

Chemical compounds of the-kind herein described are'also' of value as surface tension debe enhanced in a number may permit small pressants-in the acidization (if-calcareous *oi-l-- bearingstrata by meansof strong mineral acid'; such as hydrochloric acid. Similarly, some inem. bers are efiective as-surface tensiondepressants or'wetting agents in the floodingof exhaustedoil-bearing strata. r As-to using compounds of the kind herein described as flooding agents for recovering-oillfrom subterranean strata, reference ismade: to the procedure described in-detailin U; S. Patent No.- 2 ,226,1-l9, dated December 24, 1940, to De Greetea-nd' Keiser; As to usingcompounds of the kind herein described as demulsifiers, or in particular as surface tension depressants-in combinationwith" mineral acid or acidization ofoil-bearing strata, reference is made--- to U. S. Patent 2,233,383, dated February 25, 1941-,tdDe 'Groote and-Keiser. l It \v'ill-- be apparent to thoseskilledinthe that-residual carboxyl acidity can be eliminated by 'esterification with low -molal alcohol, for instance, ethyl, methyl, or propylaleohol; by"conventional procedure; so as to givea substantial-1y neutral product. The introduction'of such low melal hydrophobegroups does not seriously af--= feet thesolubility, and in some instancesgivesincreased resistance; to soluble calcium and magnesiu-m salts, for such propert-y isof'particular: value: Usually, however; neutralization with adil-ute solution of ammonia-or the like is just as practicable and less expensive.

In the hereto-attached claims four primary reactants are referred to," to 'wit, inonoca'rboxy hydroxy acids; monoh-ydric alcohols; polyalk-ylene' glycols; and polybasic carboxylic acids. The esters derived from the mono'car boxyhydroxy acids and the monohydric alcohols are referred to in the'claims as "alcoholic intermediates," in'-- sofar that they'contain-an alcoholiform hydroxyl radical as part of the acyl radical. The fractional esters derived from v the polyalkylene=-glycols and the poly-basic carboxyl-ioacids are referred mm the claims as acidic=intermediates; sincethey possess a'free carcoxyl" radical.- In the-hereto attached claimsthe'water soluhleester' rei'erred L i to is the product resulting from the interaction mediates; a

Having thus, described our, invention, what i we caimas 'new' and. desire. to secure by Letters,- Eatent iSJ f Y T :1 z I 1;, A wateri soluhleester, being their'esultanti o f two: intermediate reactants, m ivit',' .an acidic. intermediate reactant and an alcoholicllinteiimediate reactant; said acidic intermediatdreactantl being 'inft'urn the resultant fractional esterv of two primary reactants, one being alc.oholi'ci and the other acidicfsaid primary alcoholic" reactant consisting' o'f a polyalliylene glycol hav; ing, at least '7 and not more than 17' ether linka g sf and the alkylen'e'jr'adical thereof containin at least two and not increment carbon atoms;

o fthe aforementioned alcoholic and acidic inter ae'aaces mediate reactants being- 2 mo1es of the alcoholic intermediate-reactantforeach-mole of the.- acidic intermediate reactant;

- 2. A- watersolubleester,l sandman-em. 1; i

with; the i added proviso. that; said, ester must neutral a i 1 3. A water-soluble ester, as defined-inclaim,1.,, with the added proviso that said ester must be neutral and thatthepolybasic rprinmm reactant be a dibasiccarboxyyacid notn ore than 6- carbon atoms."

4. A water-solubleesten asidefinediin cm 1.1;;

with. the armed proviso; mam esterfl' must? neutral; that the polybasic primary! reactant r a dibasic car-boxy acidhaving' netfmo'relthan. 6:

,1 actant' b a polyethylene glycol; having; me a,

7 and notzm ore thanl'ilethelt linkazes; andthat. the intermediate alcoholic reactant, he a wa ter, insoluble ester of a moneoarbexw hydmxy qeid, and a m ai rie l n i d e atleast 19-ancL notmorethanA-Q carbon atom. 6-. A neutral: WflWl'u-SOiUblCt pound,.as defined: inclaim hand; 01th:: ing structural formula, V V f Teocnooocte mwmmewneoenw in which T- isa mozmhsidric alcaholrniclnoleia acid watereinsoluble menthe alcoholroups of, said I ester.- in J mac-1 less than 9 carbon; andtDgisj the mm acid residue; m represents. a numeral; varyingv from? to-12; and a: 1m thanlO. i r

'7. A neutral water -soluble chemical coinpound, as definedlin clnimm, and ofithe structural fonnulaz, U r .e

' Tooenacoogcaaemclmcccncoem following lawman isaQmW ,i'iclalcofifholricinoleic acid; vwaterins:lulcla radicalsv the; group of said ester being an alkyl radicalhavingi less than 9 carbon atoms; and D is the dibasic .ing structural formula:

i'n which 'I' is a, monohydsic aiooholhricimbic and the acidic primary reactant being a, p'olybasic carboiiy acid having not more than 6 carbon atoms; and thratio of the said' primary ester ifying reactants beingtvithin the range of more than 1 mole and not" over 2moles of the 'polyba'sic acidforeach mole of the polyalkylene glycolyan'd the 'said intermediate alcoholic reactant; being the esterof two additional primary reactants; and likewise, one being acidic" and the other alcoholic; towit, a- --monocarboxy-- h-yd-roxy acid; and 1 a monohydric alcohol; said intermediate alcoholic watch-insoluble ester-l radical: mnhob group of said ester being an alkyl radical hm less than 9 carbon.atoms',' and D isamaleicanid radical; "and" m represents a" numeral" varying fIOmJ'TtIL p I '.9. A: neutral; n: alchemical; pound; as .dcfineduimcl-zimfliandaottha inflame? ing structuralgiormulmz; r

I 1' aowmqww wm reactant containing at least 11-and notmore than 42 carbon atoms; theratio-of the intervarying from :7 to; 1-2.: A,

10. A neutral water-soluble chemical compound, as defined in claim 1, and o! the following structural formula:

'soluble ester, being the resultant of two intermediate reactants, to wit, an acidic intermediate reactant and an alcoholic intermediate reactant; said acidic intermediate reactant being in turn the resultant fractional ester of two primary reactants, one being alcoholic and the other acidic; said primary alcoholic reactant consisting of a polyalkylene glycol having at lest 7 and not more than '17 ether linkages; and the alkylene radical thereof containing at least two and not more than 6 carbon atoms;

and the acidic primary reactant being a polybasic carboxy acid having notv more than 6 carbon atoms; and the ratio of the said primary esterlfying reactants being within the range of more than 1 mole and not over 2 moles of the polybasic acid for each mole of the polyalkene glycol; and the said intermediate alcoholic reactant being the ester of two additional primary reactants, and likewise, one being acidic and the other alcoholic, to wit, a monocarboxy hydroxy acid, and a monohydrio alcohol, said intermediate alcoholic reactant containing at least 11 and not more than 42 carbon atoms; the ratio of the intermediate reactants being 2 moles of the alcoholic intermediate reactant for each mole of the acidic intermediate reactant; the steps of: (A) esterifying the monohydric alcohol with the monocarboxy hydroxy acid to yield the alcoholic intermediate reactant; (B) reacting the polyalkylene glycol with the polybasic carboxy acid to yield the acidic intermediate reactant; and (C) subsequently reacting said intermediate reactants to yield the water-soluble ester.

MELVIN DE GROOTE; BERNHARD KEISERL 

